Nonsighted or visually-impaired people have had difficulty in being integrated into the workforce due in part to the difficulty of working with computers to perform such tasks as word processing. In order to integrate visually-impaired people into the workforce, systems have been developed that audibly output data to the user. In these systems, a computer stores data in a file, and the user can instruct the computer to audibly output the data on a speaker so that the user may listen to the data. Such audible-output systems are difficult for users to use when listening to data of a multi-byte language. A "multi-byte language" is a language in which more than one byte is needed to uniquely identify each character of the language. In other words, there are more than 2.sup.8 (or 256) characters in the language. The characters of a multi-byte language are referred to as multi-byte characters. Multi-byte languages, such as Kanji-based languages like Chinese, Japanese and Korean, have approximately 40,000 characters.
In Kanji-based languages, the elements of grammar are known as "Kanji characters." The phrase "elements of grammar" refers to units of a given natural language that are capable of comprising parts of speech. For example, the elements of grammar in the English language are words. As such, each Kanji character is a higher-order linguistic symbol that is analogous to a word in the English language. That is, natural languages tend to have three levels of linguistic elements. The lowest of these levels depends on the specific alphabet used and is associated with the sounds of the spoken language. For example, the first and lowest level of linguistic elements in the English language comprises letters. The third level of linguistic elements is the highest level and contains those linguistic elements conveying full creative expression. In the English language, the third level comprises sentences. It is the second level of linguistic elements to which the phrase "elements of grammar" refers. The second level is an intermediate level of linguistic elements, and in the English language, the second level comprises words. In Chinese, the second level comprises Kanji characters.
Kanji characters typically comprise one or more radicals. A "radical" is a part of a Kanji character, much like letters are a part of a word. Oftentimes, a radical is itself a Kanji character. For example, FIG. 1 depicts a Kanji character 102, which means "ride," that comprises two radicals 104 and 106. Similarly, character 108, which means "money," comprises two radicals 110, 112, and character 114, which means "tree," comprises three radicals 116, 118, and 120. Of the radicals that form a character, one of the radicals is usually identified as being the primary or main radical. The main radical is usually the left-most radical in the character. However, if the radicals are situated such that one radical is above another radical, it is usually the upper radical that is the primary or main radical. Also, when a character is formed from two radicals where one radical surrounds another radical, it is the surrounding radical that is the main or primary radical. For example, the main radical for character 102 is radical 104, which means "horse." The main radical for character 108 is radical 110, which means "gold" or "metal," and the main radical for character 114 is radical 116, which means "wood." As can be seen from FIG. 1, the main radical of a character has a close relationship to the meaning of the character.
In Kanji-based languages, there are approximately 210 radicals that are used to express all the elements of grammar or characters of the multi-byte language. FIGS. 2A-2B depict a table of most of the radicals used in the Chinese language numbered from 1 to 210.
In order to facilitate the use of Chinese by English-speaking people, a well-known Chinese transliteration system, known as the "Wade-Giles system," is used to map the Kanji characters and radicals onto an English-like indication of their phonetics. For example, with reference to FIG. 1, the phonetics for character 114 are "shu4." This represents that the consonant sound "sh" is combined with the vowel sound "u as in you." The number "4" indicates the specific tone that should be used with the phonetics, such as a rising tone that is commonly associated when the speaker is asking a question. Using the Wade-Giles system, people who do not understand Chinese can phonetically sound out the language.
Because there are approximately 40,000 Kanji characters in Kanji-based languages, many groups of characters sound alike, but have completely different meanings. The characters sound alike because they have the same phonetics. For example, the following Chinese characters all sound like "wong," but each character has a different meaning:
Because many characters sound alike in multi-byte languages, when an audible-output system outputs multi-byte characters to a visually-impaired user, there is an inherent problem of ambiguity because the phonetics or sounds do not uniquely identify one character, but instead map onto a number of characters. Thus, the user oftentimes may not completely understand which characters are identified by the audio output, and consequently, the user has a difficult time understanding the meaning of the audio output. When the data is part of a rather short phrase and the user cannot determine the meaning of the character from the context of the phrase, the meaning of the audio output is even more difficult to derive. Such short phrases are often found in computer commands and are often encountered by a user when interacting with the computer. Thus, ambiguities inherent in multi-byte languages prevent visually-impaired users from using a computer to become integrated in the workforce. Sighted users do not have such a problem because each character has a different pictorial representation, and therefore, the user can identify the specific character, and hence the meaning of the specific character, from its pictorial representation. The sighted user can remember thousands of character variations because they see the characters on a day-to-day basis which helps reinforce character differences and their meaning to the sighted user. However, this visual reinforcement is not available to a visually-impaired user. It is desirable to improve multi-byte character output systems for the visually impaired so that the visually impaired can be better integrated into the work force.